Just my $0.02, but I agree with Adrian that counting ensures a consistancy from fly to fly. When you are blending colors of bucktail, that can make a difference. I find that particularly true on the "cheeks" of some pattersn where there is a difference between using three hairs of a particular color and using more...a subtle difference to be sure, but it is a difference. By counting, I find that I can control the variations in color and make it more predictable, which makes it easier to get the color effect that you want.

On the other hand, I don't think any two fish look exactly the same, so the "by eye" method should work just fine. Anyway, as Ken Abrames reminded me, there are no fly tying police.

Love learning from your flies. Thanks for posting and sharing with us all.